Telephone system



Dec. 8, 1942. R WALLER TELEPHONE SYSTEM Filed Sept. 10, 1940 lNl/E/V TORLR. WALLER- QR N at A T TORA/EV Patented Dec. 8, 1942 TELEPHONE SYSTEMLee R. Waller, Montreal, Quebec, Canada, assignor to Western ElectricCompany, Incorporated, New York, N. Y., a corporation of New YorkApplication September 10, 1940, Serial No; 356,144 (or. 179 27) 13Claims.

established by the operation of a selecting bar,

followed by the operation of a holding bar, the connection beingestablished through contacts at the intersecting point of said bars. Insuch systems connections may be established automatically between acalling subscribers line and a called subscribers line by the aid oflinks or between calling lines or called lines to or from a trunk, orconnections may be established between lines by the aid of a link over across-bar switch that is manually manipulated by an operator.

t is a feature of the present invention to provide means whereby across-bar switch may be operated automatically by the aid of anoperators equipment to establish a connection between a callingsubscribers line and 2. called subscribers;

line over a link, between a trunk and a calling line, between a trunkand a called line and between a calling line and a plurality of calledlines over a link in a conference connection.

Another feature is an arrangement of keys;

and a sequence circuit whereby when a connec-- tion between a callingline and a called line is desired, a key for the calling line and a keyfor the called line are operated in succession by the operator andwhereby the connection is then.

effected by the aid of the sequence circuit when the called line key isoperated.

Another feature is an arrangement whereby when a call between a trunkand a called line is desired a key for the trunk and a key of the:

called line are operated in succession and whereby the connection iseflected by the aid of the sequence circuit when the called line key isoperated, and when a connection between a calling line and a trunk isdesired a key for the calling line and a key for an idle trunk areoperated in succession and whereby the connection is effected by the:aid of the sequence circuit when the trunk key is operated.

Another feature is an arrangement whereby when a conference connectionis desired a special key is operated followed by the operation of thecallingline key and the called line keys and the release of the specialkey in succession and whereby the connection is effected by the aid ofthe sequence circuit when the special key is released. 1 g

The invention has been illustrated in the accompanying drawing in which:

' Fig. 1 shows a schematic representation of a system embodying theapplicants invention; and

Fig. 2 shows the detailed circuit of a system in accordance with theplan shown in Fig. 1 for establishing connections in accordance with theapplicants invention;

Referring now to the drawing and particularly to Fig. 1, a cross-barswitch ll] of any well-known type may be employed having selecting barsand holding bars for establishing the connection. The subscribers linesmay terminate in the switch in vertical rows. Two of these lines havebeen indicated at II and I2, and these lines may be connected to linksrepresented by horizontal lines; two links l3 and [4 have been indicatedwith their incoming and outgoing branches, and connections betweensubscribers lines and trunks may be established by trunks indicated byhorizontal lines, two of these trunks being shown and numbered l5 andI6. An operators equipment has been indicated at 20 and the linkcontrolling circuits have been indicated at 2| for the links l3 and M.In general, the operation of this equipment may be outlined as follows:If the subscriber of line ll desires a connection to the subscriber ofline l2 the calling subscriber will, on seizing his line, operate a linelamp 22 in the operators equipment. The operator will then actuate a key23 to an answering position thereby connecting her telephone set to thecalling line and receives from the calling subscriber the number of thedesired subscribers line. The operator then operates the key 24 of line12 to a calling position and thereby causes the link control circuit 2|to operate to establish a connection over an idle link from the callingsubscribers line ll through the switch at the cross-point 25 of the linkl3 if this link is idle to the incoming branch of this link and throughthe switch at the cross-point 26 to the outgoing branch of this link tothe called subscribers line !2. The operator then releases the keys 23and 24 to disconnect her telephone set from the connection, ringingcurrent being transmitted to the called line and when the calledsubscriber answers the connection is completed over line l3 between thecalling subscribers line H and the called subscribers line I2. When thecalling subscriber hangs up his receiver the connection through thecross-bar switch is released.

In case a connection is desired from a calling subscribers line to atrunk, a connection is established, forexample, from subscriber of lineH, by the operation of key 23 to the answering position and a trunk key,for example 29, of an idle trunk l to a calling position and thus aconnection is established through the cross-bar switch I!) from thecalling line H through crosspoint 30 over trunk l5 to the distantoffice. I The trunk busy lamp 32 may be lighted to indicate that thistrunk is in useand lamp- 22 for the calling subscriber is lighted toindicate that this line is engaged. If a connection is desired from atrunk to a line, the trunk busy lamp 32, if the call is incoming overtrunk I5, is flashed to indicate that a connection is desired. Theoperator will then operate'the key 29 to an answering position andconnect her telephone set to the trunk to receive the'desiredsubscribers numher and she will then operate the 'key 23-to the callingposition if a connection is desired to the subscriber of line H, and aconnection will then be established between the trunk l5 and line I atthe cross-point 36.

If a conference connection is desired between a calling subscriber and anumber of other subscribers, the operator, after she has ascertainedthis fact from the calling subscriber, will operate the ringing keys,such as for example, 33, of the line I2, and other similar keys to callthis line and other subscribers lines and all of these lines will thenbe connected simultaneously to the cross-bar switch of the calling lineby the operation of the special key 34 and other keys as will bedescribed hereinafter,

Detailed descriptions will now be made of these various types of callsin connection with Fig. 2. In this figure a cross-bar switch 50 has beenshown for two subscribers lines 5| and 52 terminating in vertical rowsin the switch, and one link circuit with an incoming branch 53 and anoutgoing branch 54, and one trunk circuit 58 terminating in a horizontalrow of the switch. The usual select magnet 55 for the incoming branch ofthe link and the select magnet 56 forthe outgoing branch 54 of'the linkand the select magnet 51 for the trunk 58 have been shown with theholding magnet 59 for line 5| and the holding magnet 60 for line 52.eration of a select magnet and a holding magnet causes a connection tobe established throughthe switch which may be constructed in any wellknown manner in which selecting bars and holding bars are used forestablishing the connections at the cross-points. If it is assumed thatthe subscriber of line 5| calls, the removal of the receiver by thesubscriber of this line causes a connection to be established for theoperation of the line relay 62 from battery and ground through thewindings of this relay, contacts of the cut-off relay 63, contacts ofthe ringing key 64 and the tip and ring conductors through thesubscribers loop. Line relay 62 in operating closes a flashing circuitfor the line lamp 66 from battery through this lamp, contacts of theanswering key 61 and calling key 68 associated with this subscribersline, contacts of cut-off relay63, armature and front contact of linerelay 62, interrupter 69 to ground. The operator seeing the flashing ofthis, lamp 66 will now connect her telephone set to the calling line bydesired subscriber.

the operation of the answering key 61, this connection extending overleads [2, contacts'of key 61, contacts of cut-off relay 63, contacts ofringing key 64 to the line 5|. The operation of the answering key 61opens the flashing circuit for the line lamp 66. The subscriber of line5| now informs the operator of the number of the The operator thenoperates the calling key 13 of the subscribers line 52 if thecorresponding subscriber is desired. This starts operations to establisha connection between the calling subscriber and the called subline 5|.

scriber by the operation of the link control circuit indicated in Fig. 1by numeral 2| and consisting of a number of relays as will be described.The first eifect will be the operation of the first relay 14 of theseries of sequence relays l4, I5, 16' and Tl. The circuit for relay 14extends from battery through the winding of the holding magnet60 of thecalled line, contacts of keys l3 and H23, winding of relay 14 to ground.The resistance of the winding of relay I4 is such that the holdingmagnet 60 will not operate at this time. If now the link shown is idlethe select magnet for the incoming branch 53 of this link'will beoperated from battery through the winding of magnet 55, contacts of linkrelay 18, contacts of the calling key 19 of the trunk 58 as shown, thisconnection to key 19, however, extending through corresponding contactsof similar keys for other trunks to open this circuit when any of thetrunks is taken. for use and from there through the answering key 80 ofthe trunk shown, contacts of relays 14 and 16 to ground. Relay 14 alsocloses an obvious circuit for the operation of relay 15 which is slow inoperating, to permit the select magnet 55 time to operate before thisrelay operates. Relay 15 in operating closes a circuit for the holdingmagnet 59 of the calling subscribers line from battery throughthewinding of this magnet, contacts of answering key 61 and contacts ofrelay 75 to ground, thus establishing a connection at the cross-point 82between the outgoing branch 53 of the link shown for the callingsubscribers Magnet 59 in operating closes a circuit from ground over thecircuit as traced at contacts of relay 15 through the winding of thecutoff relay 63 to battery causing the operation of this relay toconnect the calling line 5| to' the cross-point 82 and the incomingbranch 53 of The opcuit for line relay 62 which now releases anddisconnects the operators set HI from the calling line. Relay 15 alsocloses a circuit for the operation of relay '76, this relay being slowin operating to permit the operation of the abovementioned magnet 59 andrelay 63. Relay 16 in operating opens the circuit for the select magnet55 which now releases, and also closes a circuit for the select magnet56 of the outgoing branch 54 of the link shown, from battery, winding ofthis magnet, contacts of relays 18 and 16 to ground. Relay 16 alsocloses an obvious circuit for the operation of relay 11 which is slow inoperating to permit the operation of the select magnet 56. When relay 11operates a circuit to ground is established at the outer righthandarmature and front contact of this relay to shunt relay (4 and tooperate the holding magnet 60 of thecalled line 52 from battery, windingof this magnet, contacts of key 13 to ground at relay Tl. Relay 14 isconsequently released and causes the release in succession of relays 15,16 and TI. The operation of the holding magnet 69 now establishes aconnectionat the cross-point 84 for the calling line 52' and theoutgoing branch 54 of the link shown. The holding magnet 69 in operatingcloses a circuit for the cut-off relay 85 from battery, winding of thisrelay, contacts of magnet 69 to ground at relay 11. In the meantime as aresult of the operation of the cut-01f relay 63 the circuit establishedfrom the calling subscribers line 5| through the cross-point 82 to theincoming branch of the link will operate relay 86 from battery andground over the loop to the calling subscriber. This relay in turncloses an obvious circuit for relay 8'! and this relay in operatingcloses a locking circuit to ground for the holding magnets 59 and 69 andcut-off relays 83 and 85 over contacts at the cross-point 82 for holdingmagnet 59 and cut-off relay 63 and over the contacts at cross-point 84for the holding magnet 69 and the cut-off relay 85. As noted the cut-offrelay 85 connects the called line at its contacts through cross-point 84to contacts of relay 89. Relay 89 will now'operate'on the operation ofrelay 81 from battery, winding of relay 89, contacts of relay 99 toground at the contacts of relay 81. Relay 89 in operating connects theringing circuit from ground and a ringing source connected at 9| overthe tip and ring conductors over the cross-point 84, contacts of relay85, ringing key 92 of the called line over the tip and ring conductorsof this line to the called subscriber to ring his bell. As hereinbeforede scribed, on the release of relay "l4 relays 15, 19 and 11 releasedand on the release of relay I6 prior to the release of relay 11 it willbe noted that a circuit will be completed momentarily for the operationof relay 18 from battery through make-before-break contacts of thisrelay, contacts of relay 11 when operated and contacts of relay '16 whenreleased to ground. Relay 1.8 inoperating closes a locking circuit foritself from battery winding and contacts of relay 81 to ground. Relay 18transfers the operating leads for the select magnets 55 and 56 tocontacts of relay 93 which correspond to relay 18 and is associated withthe next link, so that on the next call the next succeeding link will beseized and relay 18 will also close an obvious circuit for the link lamp94.

When now the called subscriber of line 52 ,9

of relay 89 when it releases between ringing-impulses as the circuit forthis relay is controlled through an interrupter 95, windings of relay 96to battery and ground. Relay 96 in operating closes an obvious circuitforthe operation of relay 99 which opens the circuit forrelay 89 whichis then permanently released and this relay 99 is looked over its owncontacts to ground at relay 8'|.- The conversation between the callingsubscriber of line 5| and the called subscriber of line 52 may now takeplace across the condensers 9B, talking battery being supplied for thecalling subscriber through the windings of relay 86 and for the calledsubscriber through the windings of relay 96. The operator may nowrestore the keys 51 and I3. conversation when the calling subscriber ofline 5|, for example, hangs up, relays 86 and 81 will release causingthe release of the holding magnets 59 and 69, cut-off relay 6 3 and 85,and relay I8 which extinguishes the link-busy lamp 94,

At the end of the normal,

3 returning the'switch so and the link shown to a If a connection isdesired from a subscriber to a trunk such as fromthe calling subscriberof line 5| and trunk 58 if idle, the connection may be established ashereinbefore described to connect theoperators telephone 19 to the line5| and when the calling subscriberindicates that a trunk'connection isdesired, thev operator will actuate the calling key 1901? trunk 58 ifthis trunk is idle. The efiect of the operation of key '19 in this caseis that the trunk 58-will be connected 'to the calling line 5| by firstcausing the operationof the relay M from battery at 99, contacts of key19, key |93,-winding of relay M to ground. Relay I4 nowin operatingcloses a circuit for the operation of select magnet 51 of the trunk 58from battery through'the winding of this magnet, contacts of key 19,contacts of the key 89, contacts ofrrelays 14 and 19 to ground. Relay 14now operates relay 15 after an interval and this relay closes aconnection for'the operation of holding magnet 59 from battery throughthe winding of this magnet,'contacts of key 61 and contacts of relay 15to ground. Magnet 59 closes the above-mentioned circuit for the cut-offrelay 63 which connects the calling line 5| through contacts of thisrelay over the cross-point |99tip and'ring conductors ofthe trunk 58'through the winding of relay |9|, contacts of keys 89 and 19 to batteryand ground (not shown) atthe operators telephone set 19 to cause theoperation of relay |9|. Re-

lay:| 9|' operates relay I92 over an obvious cir- "cuit; This relaycloses an obvious circuit for the'trunk-busy lamp I93 which indicatesthat i this trunk is now in use. Relay I92 also establishes a connectionto ground for shunting the battery 99 so that relay 14 will release. It

should, of course, be observed that when relay 16 operates after theoperation of relay 15, the circuit for the select magnet '51 is open,while the holding magnet 59 and relay B3 are locked over contacts atcross-point I99 and ground applied at contact of relay |92to maintainthe established connection. The operator may now release the key 19and-connect the trunk 58 through to the calling station through contactsof keys 19 and 89 and as is usual, in circuits of this kind battery andground will be supplied at the distant endof this trunk to maintainrelays |9| and IGZ operated. The circuits may now be prepared in anywell-known manner to permit a connection to be established and usualdial tone will be applied so that the calling subscriber of line 5| maynow dial the desired number at the distant station. -The operator willalsorelease the key 61 to permit the line lamp 66 to be lighted steadilyfrom ground at contacts of relay 93 to show that this line is engaged,while the trunk-busy lamp I93 indicates that the trunk 58 is busy. Ifthe calling subscribers line is not provided with dialing equipment theoperator may dial over the -trunk. In this case the operator will firstopen the key I93 after she has received theinformation from the callingsubscriber that a trunk connection is desired and dial from her set 19through contacts of key 19 when she operates this key, The opening ofkey I93 prevents the connection of the calling line to-trunk 58 at thecross-point |99 as described.- When the operator has established aconnection at the distant end she will release key I93 so that relay I4may operate and establish the connection as described at the crossthecalling subscriber of line be a restricted subscriber-who is notentitled to outside calls, theoperator-will, of course, not establishthe trunk connection desired. "The releaseof the trunk connection maytake place-by the subscriber of line I5| replacing the receiver-thusreleasingrelays Inland N12 to release the holding magnet59 andextinguishlamp I62. and release relayj63 to'extinguish'lamp 66.

If a call is incoming over a trunk for a connectionito a desiredsubscribers line the seizing of the trunk-58 for example at the distantend, causes the operation of -the alternating current relayi|-08over'thetip and ring-conductors, contacts of keys #9 and BU and-contactsof relay I02, condenser lill'and winding of relay I06. This relay closesan obvious circuit for the operation of relay'IflB which now-locks overits contacts over contacts of keys 8lJ-and- '|9 to ground and closesa-circuitfrom an interrupter I09 over contacts of relay |02,lamp' I03 tobattery and ground, causing this lamp to flash to indicate that a callis waiting on this trunk. In answering this call the operator .actuatesthe key 89 and connects her telephone set to the trunk over contacts ofthis key. The subscriber at the distant'end of trunk '58-now gives theoperator the number of the desired subscribers line and if line 5| isdesired theoperator actuatesringing key'6 l to ring the subscriber ofline 5| by applyingringing current atthe contacts of this-ringing key.'When. the operator releases ringing key 64 and the subscriber of line5| answers relay.62 is operated to cause the line'lamp'BE to flash overa circuit 'as hereinbefore described. When the operator notices thefiashing'of lamp 66 she will operate the key"68 of line 5| and thusclose a circuit for the operation of relay 14 from battery through thewinding of holding magnet 59, contacts of 'key 68; winding of relay 14to ground.

Magnet 59 does not operate in this circuit. Relay 14 in operatingcloses'a circuit? for the operation of select'magnet 51 from batterythrough the winding of this magnet, contacts of key 80, contactsof'relays l4 and 16 to ground. When relay operates due to the operationof relay 14 a circuit is completed'for the operationof holding magnet59from battery'through the winding of this magnet, contact of keys 68 and60 an'dcon- F 'tacts of relay 15 to ground. It should be noted that thiscircuit'to ground on contacts of relay l5 shunts the winding of relay Mwhich now releases. Magnet 59 now establishes a connection between thecalled subscribers line 5| and the trunk 58 at the cross-point 109 andcauses the operation-of the cut-off relay 63 which releases line relay62 and'connects the line 5| to the trunk'58 at its contacts. Thisconnection causes the operationof relay |il| over the tip and ringconductors of the subscribers loop through contacts'of key 80 to batteryand ground at the operators telephone set. Relay |ll| operates relay I02which'lightsthe trunk-busy lamp Hi3 with a steady light to indicate thatthe trunk is busy. 'The operator then releases the" keys 8!] and B8 andthe line 5| is connected to the trunk 58 through contacts of keys 80 and19.

In case a conference connection is desired between a number ofsubscribers, the answering key, for example 61, of line 5|, is operatedif the call is incoming over line 5| and the calling subscriber of line5| will then inform the operator that a conference connection is desiredbetween his line and a number of other'lines. The oper- 1point 00 andthen release keys 6! and 19." Should =-ator then proceeds to ring theseother lines by operating-their ringing keys, such for example key 92 ofline 52. After shehas rung the numbers of such subscribers she'willoperate their calling keys,'such as 13 for example of line 52,after firsthaving opened the connection through key: N33 to prevent theestablishing of any connections until all the calling keys havebeenoperated. 'After such keyshave been operated the operator willrestore key Hi3 and thereby cause the operation of relay" to starttheoperation of-the circuits to establish a conference connection. It willbe noted that in this case the procedure will bethe-same as in aline-tolineconnection except that as keys, such as H9 of' the calledsubscribers lines are operated, all holding magnets'corresponding toholding magnet .60 for line 32 willbe operated through con-.tacts-of'keyssuch as |0'of the corresponding lines .to ground at relay15 when this relayoperates. Thusit will be seen that when relay 11operates, holding magnet-59 will be operated to establish a. connectionbetween the'calling line 5| at the'cross-point 82 of link which is theone that was seized and the holding'magnets corresponding to holdingmagnet fifi of all the called lines will be operated as mentioned frombattery throughthe windings of these magnets and their correspondingkeys, such as H0 for line 52 andcontacts of relay '15 when this relayoperates, and thereby cause the connection to be established atcross-points, such as 84, for the outgoing branch of the link as-shown,and the calling subscribersline-5l will therefore be connected to 'all'the other called lines throughthe link, the calling line being connectedat crosspoint'82 to the incoming-branch and the called lines to theoutgoing branch at cross-point 84 and other similar points for'the otherlines. The operator may thenrelease all the keys actuated andconversation between the conference lines may take place in the samemanner as described in connection with line-to-line calls.

What is claimed is:

1. In a telephone system, a switch, lines and links terminated therein,magnets in said switch for actuating it'to connect lines in said switchthrough a link, a key for each line, means controlled by the actuationof the key for a calling line andthe key for a called line for actuatingmagnets in said switch'to establish a connection between the callingline and the called line through an idle link over said switch saidmeans being so arranged that the calling line and the called line areconnected to said link after the key for the called line is actuated.

2. In a telephone system, a cross-bar switch, lines and linksterminating in said switch, magnets in said switch for actuating it toconnect linesin said switch through a link, a key for each line, meanscontrolled by the operation of the key for a calling line and the keyfor a called line for actuating said magnets to first establish aconnection between the calling line and an idle link through-said switchand then establish a connection between the called line and said linkthrough said switch, said means being operative to actuate said magnetsonly after the key for the called line has been actuated.

3.'In a telephone system, a switch, lines and links terminating in saidswitch, magnets in said switch for actuating it to connect the lines insaid switch through an idle link, a'key for each line, a series ofrelays, circuit means for operating said relays ina certain sequence,means controlled by the operation of the key for a calling line followedby the operation ofthe key for a called line for starting the operationof said relays in sequence after the key for the called line has beenoperated and circuit means controlled by said keys and said relays whenoperated in sequence for actuating said magnets in a certain sequence toestablish a connection between said calling line and said called linethrough an idle link over said switch.

4. In a telephone system, a, cross-bar switch, lines and linksterminating in said switch, magnets in said switch for actuating it toconnect lines in said switch through a link, a series of relays, acircuit means for operating said relays in a certain sequence, a key foreach line, circuit means controlled by the operation of the key of acalling line followed by the operation of the key of a called line forstarting the operation of said relays in sequence, and means controlledby said operated keys and said relays for actuating said magnets in acertain sequence to establish a connection between the calling line andthe called line through a link over said switch, the starting of theoperation of the relays in sequence taking place when the key for thecalled line is operated.

5, In a telephone system, a cross-bar switch, lines and linksterminating in said switch, magnets in said switch for actuating it toconnect lines in said switch through a link, a key for each line, aseries of relays, circuit means for operating said relays in a certainsequence, means controlled by the operation of the key of a calling lineand the key for a called line for starting the operation of said relaysin sequence and circuit means controlled by said operated keys and saidrelays for first operating magnets in said switch for establishing aconnection between the calling line and an idle link followed by theoperation of magnets in said switch to establish a connection betweenthe called line and said link, operative on the operation of the key forthe called line.

6. In a telephone system, a switch, lines, trunks and links terminatingin said switch, magnets in said switch for actuating it to connect aline to a link or a line to a trunk, a key for each line, a key for eachtrunk, means controlled by the operation of the key for a calling lineand a key for a called line for actuating said magnets to establish aconnection between the calling line and the called line through a linkover said switch operative when the key for the called line is actuated,means controlled by the operation of the key for a calling line and akey for a trunk for operating said magnets to establish a connectionbetween said calling line and said trunk and operative when the key forthe trunk is actuated.

'7. In a telephone system,ia cross-bar switch, lines, trunks and linksterminating in said switch, magnets in said switch for actuating it tointerconnect lines through a link and a line to a trunk, a key for eachline, a key for each trunk, means controlled by the operation of the keyfor a calling line and the key for a called line for actuating saidmagnets to establish a connection between said calling line and saidcalled line through an idle link over said switch operative when the keyfor the called line is actuated and means controlled by the operation ofthe key for a trunk and the key fora calling line for establishingconnections from said trunk to said called line 75 said magnets toestablish a connection over said switch between said calling line andsaid called lines over a link operative when the separate key isreleased.

9. In a telephone system, a cross-bar switch, lines, links terminatingtherein, magnets in said cross-bar switch for actuating the switch toconnect lines in said switch through a link, a key for each line, aseparate key, means for calling a plurality of said lines, meanscontrolled by the operation of the separate key, the key of a callingline and the keys of the called lines and the release of the separatekey for actuating said magnets to establish a connection over saidswitch between said calling line andrsaid called lines over a linkoperative when the separate key is released, connections between thecalling line and the links preceding the connections between the linkand the called lines, said connections between the link and the calledlines occurring simultaneously.

10. In a telephone system, across-bar switch, lines and linksterminating in said switch, magnets in said switch for actuating it toconnect lines in said switches through a link, a key for each line, aspecial key, means controlled by the operation of said special keyfollowed by the operation of the key of a calling line and the operationof the keys of a plurality of called lines and the subsequent release ofthe special key for actuating magnets of said switch to establish aconnection between the calling line and a link and for actuating magnetsin said switch to establish connections between the called lines andsaid link simultaneously, said operation of all of said magnets in saidswitch being efiective on the release of the special key.

11. In a telephone system, a switch, lines and links terminatingtherein, magnets in said switch for actuating it to connect lines insaid switch through said links, a key for each line, means for firstactuating certain magnets for connecting a calling line to an idle linkand then actuating certain other magnets for connecting said called lineto said link, said operating means for said magnets being controlledjointly by the operation of the key for a calling line and the key for acalled line to actuate said magnets after the key for the called linehas been operated.

12. In a telephone system, a switch, lines and links terminatingtherein, magnets in said switch for actuating it to connect lines insaid switch through a link, an operators position, a key for each line,means controlled by theactuation'of the key for a calling line forconnecting said operators, position to said calling line, meanscontrolled by said actuation of the key for the calling line and theactuation of the key for a called line, for actuating said magnets toestablish a connection between the calling line and the called linethrough an idle link and for disconnecting said operators position fromsaid called line.

13. In a telephone system, a switch, lines and links terminatingtherein, magnets in said switch for actuating it to connect lines insaid switch through a link, an operators position, a key for each line,means controlledby the actuation of the key for a calling line forconnecting said operators position to said calling line, meanscontrolled by said actuation of the key fo the calling line and theactuation of the key for a called line, for actuating said' magnets toestablish a connection between the calling lineand the called linethrough an idle link andfor disconnecting said operators position fromsaid called line, said means being efiecti've when the key for thecalled line is actuated.

' LEER. WAILER

